The invention relates generally to surface mounted connectors on printed circuit boards, and more specifically to a contact for ball grid array connectors.
The ongoing trend toward smaller, lighter, and higher performance electrical components and higher density electrical circuits has led to the development of surface mount technology in the design of printed circuit boards. As is well understood in the art, surface mountable packaging allows for the connection of the package to pads on the surface of the circuit board rather than by contacts or pins soldered in plated holes going through the circuit board, and surface mount technology allows for an increased In order to meet the increasing performance requirements, component density on a circuit board, thereby saving space on the circuit board.
The ball grid array (BGA) is one particular type of surface mount package that has developed in response to the demand created by higher density electrical circuits for increased density of electrical connections on the circuit board. The ball grid array includes an array of connections on the bottom side of the connector package. In the ball grid array, pins extending into the circuit board are replaced by small solder balls placed on the bottom side of the connector at each contact location. The circuit board, rather than holes, has an array of contact pads matching the solder ball placements on the connector bottom. Connections are made by reflowing the solder balls to mechanically and electrically engage the connector to the circuit board.
BGA technology offers the advantages of higher connection densities on the circuit board and higher manufacturing yields which lowers product cost. However, BGA technology is not without disadvantages. For instance, solder joints cannot be easily inspected, and as a result, the design and assembly processes must be controlled to maintain the high yields and product reliability. Also, the contacts in the BGA connectors are generally unitary in design which limits design options when developing new BGA connectors.